The Los Angeles County Coroner ruled Thursday that the final cause of Whitney Houston's death was drowning, as well as from effects of atherosclerotic heart disease and cocaine use.

According to Chief Medical Examiner Anthony T. Hernandez's report, there was no foul play involved in the Feb. 11 death of Houston. She was found submerged in a bathtub filled with water at the Beverly Hills Hilton just hours before she was due to perform at Clive Davis' Grammy Party.

Toxicology reports found metabolites also contributed to her death. Traces of marijuana and the prescription drugs Xanax, Flexiril and over-the-counter Benadryl were also found in her system, but did not play a role.

The announcement Thursday ends weeks of speculation about what killed the Grammy-winning singer.

Several bottles of prescription medications were found in her hotel room, but coroner's officials said they weren't in excessive quantities.

Coroner's spokesman Craig Harvey says the results indicated Houston was a chronic cocaine user.

The singer was buried in a New Jersey cemetery next to her father after an emotional four-hour funeral service that was attended by friends, family and superstars such as Oprah Winfrey, Tyler Perry, Alicia Keys, Mariah Carey, Mary J. Blige, Jennifer Hudson and Roberta Flack

Houston, a sensation from her first, eponymous album in 1985, was one of the world's best-selling artists from the mid-1980s to the late 1990s, turning out such hits as "I Wanna Dance With Somebody," `'How Will I Know," `'The Greatest Love of All" and "I Will Always Love You." But as she struggled with drugs, her majestic voice became raspy, and she couldn't hit the high notes.

Interest in her music has skyrocketed since her death, pushing her songs back on to charts and into heavy rotation on the radio.

The Associated Press contributed to this report.